Improved stand structure characterization from nested plot designs in the Spanish National Forest Inventory

2020 ◽  
Author(s):  
Daniel Moreno-Fernández ◽  
Isabel Cañellas ◽  
Iciar Alberdi ◽  
Fernando Montes
Keyword(s):  
Spatial Pattern ◽  
Null Model ◽  
National Forest Inventory ◽  
Second Order ◽  
Order Moment ◽  
National Forest ◽  
Nearest Neighbour ◽  
Nested Design ◽  
Forest Inventories ◽  
Moment Functions

Abstract National forest inventories, in which trees are often mapped within the plots, provide a tool for the quantification of large-scale forest structure since they cover all forest areas. Many National Forest Inventories follow a nested design in order to reduce the sampling effort for smaller trees. We propose and test a methodology that allows the spatial pattern of trees, species mingling and size differentiation to be characterized using the nearest neighbour indices and second-order moment functions from nested plot data. The nearest neighbour indices and second-order moment functions for the actual distribution are compared with simulations of the appropriate null model: spatial randomness for spatial pattern characterization or spatial independence for species mingling and size differentiation. The proposed method consists of constraining the null model to fit the nested plot design. For the purposes of the study, we simulated 120 plots and used 26 real plots located in pure and mixed stands in Central Spain, for which a complete census with detailed information about trees was available. The nested design used in the Spanish National Forest Inventory (SNFI) plots was simulated to test the performance, taking the complete census as reference. Despite of the limited accuracy for some structural measures, the proposed method based on nested design data performed better for most of the nearest neighbour indices and second-order moment functions than the strategy currently used in the SNFI for structure assessment in a subsample of SNFI plots, consisting of mapping the 20 trees closest to the plot centre. Nearest neighbour indices provided greater accuracy for species mingling assessment than second-order moment functions, whereas the opposite occurred when describing spatial pattern and size differentiation. The methodology proposed provides the first insight into the characterization of forest structure in nested designs although more evaluations are required for different forest types.

scholarly journals Zur Auswirkung der Hangneigungskorrektur auf Schätzwerte im Schweizerischen Landesforstinventar (LFI) | Investigation of the effect of the slope correction method as applied in the Swiss National Forest Inventory of estimates

2001 ◽  
Vol 152 (6) ◽  
pp. 215-225 ◽  
Author(s):  
Michael Köhl ◽  
Peter Brassel
Keyword(s):  
Forest Inventory ◽  
Basal Area ◽  
Correction Method ◽  
National Forest Inventory ◽  
National Forest ◽  
Average Deviation ◽  
Forest Inventories ◽  
Slope Correction ◽  
Number Of Stems ◽  
Elliptical Area

For forest inventories on slopes, it is necessary to correct the test areas, because the circular areas, when projected, become elliptical. Based on 93 samples from the Swiss National Forest Inventory (FNI), it was determined whether the simplified method, which increases the radius to match that of the elliptical area, leads to a distortion of the results. An average deviation of 2% was found between the FNI estimated values and the actual values for the basal area and the number of stems. For estimations of smaller units, greater distortions of the results are expected.

The applicability of national forest inventories for estimating forest damage outbreaks – Experiences from a Gremmeniella outbreak in Sweden

2006 ◽  
Vol 36 (10) ◽  
pp. 2605-2613 ◽  
Author(s):  
Sören Wulff ◽  
Per Hansson ◽  
Jesper Witzell
Keyword(s):  
Geographical Distribution ◽  
Pinus Contorta ◽  
National Forest Inventory ◽  
Forest Damage ◽  
Distribution Area ◽  
National Forest ◽  
Accurate Identification ◽  
Forest Inventories ◽  
Shoot Blight ◽  
National Forest Inventories

The design of the Swedish National Forest Inventory as well as the National Forest Damage Inventory is a sparse sample of systematically allocated plots. In this study data were combined from these two independent inventories to estimate geographical distribution, area extension, and disease development of a Gremmeniella abietina (Lagerb.) Morelet epidemic. For the combined data the standard error for estimated total area of affected Scots pine (Pinus sylvestris L.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var.latifolia Engelm.) forests was about 11%. Assessments of the proportion of pine trees with fresh shoot blight infection shows that changes larger than 1% are significantly (p < 0.05) estimated. By testing in pairwise cross inventory, it was shown that the accuracy of the assessment of total shoot blight symptoms was fairly good in 2001–2002, with a κ statistic of 0.59–0.61. Severely damaged trees were identified with an agreement of κ = 0.81. The total area of pine forest both slightly and severely affected by G. abietina during 2001–2003 was estimated to be 484 000 ha. Three geographically separate damage centres were distinguished. Thus, despite a relatively sparse sample plot density, the national forest inventories have good potential for estimating the geographical distribution, areal extent, and dispersal of extensive damage outbreak. Results are dependent on the inventories being carried out with an accurate identification of target objects.

scholarly journals A century of national forest inventories – informing past, present and future decisions

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Johannes Breidenbach ◽  
Ronald E. McRoberts ◽  
Iciar Alberdi ◽  
Clara Antón-Fernández ◽  
Erkki Tomppo
Keyword(s):  
Forest Inventory ◽  
Policy Making ◽  
Terrestrial Ecosystems ◽  
National Forest Inventory ◽  
100Th Anniversary ◽  
Future Research ◽  
National Forest ◽  
Forest Inventories ◽  
National Forest Inventories ◽  
Over Exploitation

AbstractIn 2019, 100 years had elapsed since the first National Forest Inventory (NFI) was established in Norway. Motivated by a fear of over-exploitation of timber resources, NFIs today enable informed policy making by providing data vital to decision support at international, national, regional, and local scales. This Collection of articles celebrates the 100th anniversary of NFIs with a description of past, present, and future research aiming at improving the monitoring of forest and other terrestrial ecosystems.

scholarly journals The National Forest Inventory of Serbia: State and possible further directions of development

2015 ◽  
pp. 9-32
Author(s):  
Damjan Pantic ◽  
Dragan Borota
Keyword(s):  
National Forest Inventory ◽  
National Forest ◽  
Successful Implementation ◽  
Forest Inventories ◽  
Harmonization Process ◽  
Process Adaptation ◽  
National Forest Inventories ◽  
Methodological Problems ◽  
Definition Of ◽  
Further Development

A comparative analysis of National Forest Inventories (NFI) of many countries, including Serbia was made in the manuscript, in terms of methodology and in terms of the definition of different information collected about forest ecosystems. Further development of the NFI Serbia was also analyzed. It was determined that there are differences in national methodologies, but that they are not substantial and do not constitute an obstacle to the creation of uniform databases of forests at the regional and global levels as a prerequisite for political and professional action aimed at protecting and ensuring sustainability of all forest functions. Contrary to that, differences between national definitions for information that are collected by inventory are numerous, distinct and as such represent a major obstacle to the mentioned aspirations. The solution of the problem is standardization, i.e. in the far more acceptable harmonization process (adaptation) NFI, whereby such frameworks of that activity are imposed by the FAO (globally) and COST Action E43 (mainly in the European region). NFI Serbia, on the threshold of second realization, is burdened with a numerous institutional, organizational and methodological problems and dilemmas, inherited from the first measurement of Serbian forests. Therefore, an urgent recruitment of relevant experts is necessary to resolve and overcome problems, in order to ensure all the prerequisites for a successful implementation and obtaining reliable data of the second NFI, so that the future NFI can be alleviated of the conditions in which it is currently located.

Design-based regression estimation of net change for forest inventories

2015 ◽  
Vol 45 (12) ◽  
pp. 1775-1784 ◽  
Author(s):  
Alexander Massey ◽  
Daniel Mandallaz
Keyword(s):  
National Forest Inventory ◽  
Time Span ◽  
Permanent Plots ◽  
National Forest ◽  
Regression Estimation ◽  
Indirect Methods ◽  
Indirect Estimation ◽  
Direct Estimation ◽  
Forest Inventories ◽  
Regression Estimators

A simple design-based approach to estimating net change of a forest attribute such as timber volume is to observe the change directly on the plot level and then make that the response variable of interest using established estimation techniques such as multiphase regression estimators. This direct approach is only possible for inventories with permanent plots and is constrained to estimating net change over time periods matching the duration of the remeasurement cycle. Indirect estimation involves applying one of the aforementioned techniques to estimate the state at two time points and taking their difference. Indirect methods, although less common, are not necessarily constrained to permanent plots and can estimate net change over any desired time span for annual designs. This article compares design-based direct and indirect regression estimators under the Monte Carlo approach and illustrates their performances with data from the Swiss National Forest Inventory. The major finding is that direct estimation should be preferred whenever change is observable directly on the plot level but that multiphase indirect estimation can still improve precision when direct estimation is not possible such as for inventories employing only temporary plots.

scholarly journals Lessons learned from assessing the cover and yield of bilberry and lingonberry using the national forest inventories in Finland and Sweden

Silva Fennica ◽  
2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Jari Miina ◽  
Inka Bohlin ◽  
Torgny Lind ◽  
Jonas Dahlgren ◽  
Kari Härkönen ◽  
...  
Keyword(s):  
National Forest Inventory ◽  
Lessons Learned ◽  
Accurate Information ◽  
National Forest ◽  
Management Scenarios ◽  
Model Based ◽  
Forest Inventories ◽  
National Forest Inventories ◽  
Forecasting System ◽  
Development And Management

Bilberry ( L.) and lingonberry ( L.) can be a part of healthy diet and are important for many animals. Two approaches are described to assessing their vegetation cover and berry yield via national forest inventory (NFI) observations. The aim was to provide estimates and predictions of the abundance and yield of the species at regional and national levels in Finland and Sweden. In Finland, the model-based predictions are used in evaluating the impacts of cutting intensity on forest berries needed in forest-related decision making. In Sweden, seasonal inventory-based estimates are used to evaluate the annual national and regional berry yields, and in a forecasting system aimed at large public and berry enterprises. Based on the NFI sample plots measured between 2014 and 2018, the total annual yields are estimated to be 208 Mkg of bilberry and 246 Mkg of lingonberry on productive forest land (increment at least 1 m ha year) in Finland, and 336 and 382 Mkg respectively in Sweden (average of NFI inventories in 2015–2019). The predicted development of berry yields is related to the intensity of cuttings in alternative forest management scenarios: lower removals favoured bilberry, and higher removals lingonberry. The model-based method describes the effects of stand development and management on berry yields, whereas the inventory-based method can calibrate seasonal estimates through field observations. In providing spatially and timely more accurate information concerning seasonal berry yields, an assessment of berry yields should involve the elements of both inventory-based and model-based approaches described in this study.Vaccinium myrtillusV. vitis-idaea3–1–1

Steigende Bestandszahlen bei Spechten und anderen Vogelarten dank Zunahme von Totholz? | An increase in the population of woodpeckers and other bird species thanks to an increase in the quantities of deadwood?

2009 ◽  
Vol 160 (11) ◽  
pp. 334-340 ◽  
Author(s):  
Pierre Mollet ◽  
Niklaus Zbinden ◽  
Hans Schmid
Keyword(s):  
Forest Inventory ◽  
Bird Species ◽  
National Forest Inventory ◽  
Population Increase ◽  
National Forest ◽  
Forest Species ◽  
Breeding Populations ◽  
Willow Tit ◽  
Middle Spotted Woodpecker ◽  
Important Habitat

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.

scholarly journals Harmonising, improving and using social and recreational data in National Forest Inventories across Europe

2020 ◽  
Vol 77 (3) ◽  
Author(s):  
Mark A. Atkinson ◽  
David M. Edwards ◽  
Frank Søndergaard Jensen ◽  
Alexander P. N. van der Jagt ◽  
Ben R. Ditchburn ◽  
...  
Keyword(s):  
National Level ◽  
European Countries ◽  
Transport Infrastructure ◽  
National Forest ◽  
Qualitative Response ◽  
Forest Inventories ◽  
Recreational Services ◽  
National Forest Inventories ◽  
Funded Project ◽  
General Transport

Abstract Key message National Forest Inventories (NFIs) hold promise for monitoring and valuing of non-productive forest functions, including social and recreational services. European countries use a range of methods to collect social and recreational information within their NFI methodologies. Data collected frequently included general and recreation-specific infrastructure, but innovative approaches are also used to monitor recreational use and social abuse. Context Social and recreational indicators are increasingly valued in efforts to measure the non-productive value of forests in Europe. National Forest Inventories (NFIs) can be used to estimate recreational and social usage of forest land at a national level and relate this use to other biophysical, spatial and topographical features. Nonetheless, there is little information concerning the extent. Aims The study aims to identify the coverage of social and recreational data present in European NFIs including the types of data recorded as part of the NFI methodologies across European countries. It also aims to examine contrasting methods used to record social and recreational data and present recommendations for ways forward for countries to integrate these into NFI practice. Methods A pan-European questionnaire was designed and distributed to 35 counties as part of the EU-funded project Distributed, Integrated and Harmonised Forest Information for Bioeconomy Outlooks (DIABOLO). The questionnaire probed countries on all social and recreational data that was included within NFIs. Qualitative response data was analysed and recoded to measure the extent of social and recreational data recoded in European NFIs both as a function of the number of variable categories per country and the number of countries recording particular variables. Results Thirty-one countries reported at least one social or recreational variable over 12 categories of data. The most frequently recorded variables included ownership, general transport infrastructure and recreation-specific infrastructure. Countries collecting data over many different categories included Switzerland, Great Britain, Czech Republic, Luxemburg and Denmark. Conclusion The study proposes a specific set of indicators, based upon countries with well-developed social and recreational data in their NFIs, which could be used by other countries, and report on the extent to which these are currently collected across Europe. It discusses results and makes a series of recommendations concerning priorities for the inclusion of social and recreational data in European NFIs.

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